US20160353020A1 - Optical system and imaging system incorporating the same - Google Patents
Optical system and imaging system incorporating the same Download PDFInfo
- Publication number
- US20160353020A1 US20160353020A1 US15/137,404 US201615137404A US2016353020A1 US 20160353020 A1 US20160353020 A1 US 20160353020A1 US 201615137404 A US201615137404 A US 201615137404A US 2016353020 A1 US2016353020 A1 US 2016353020A1
- Authority
- US
- United States
- Prior art keywords
- wide angle
- area
- optical system
- lens
- view
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H04N5/23238—
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/06—Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/04—Prisms
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/45—Cameras or camera modules comprising electronic image sensors; Control thereof for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/698—Control of cameras or camera modules for achieving an enlarged field of view, e.g. panoramic image capture
-
- H04N5/23293—
Abstract
An optical system including a plurality of wide angle lenses, each having a peripheral area with a decreased magnification per unit angle of view and an inside area ranging from an optical axis to an inside edge of the peripheral area. The inside area includes a first area ranging from the optical axis toward the peripheral area, the first area having a constant magnification per unit angle of view and a second area ranging from an outside edge of the first area to the inside edge of the peripheral area. The second area has a magnification per unit angle of view that continuously varies in a direction from the outside edge of the first area toward the peripheral area. An image portion formed by the peripheral area overlaps with another image portion formed by the peripheral area of another wide angle lens.
Description
- This patent application is based on and claims priority pursuant to 35 U.S.C. §119(a) to Japanese Patent Application No. 2015-105614, filed on May 25, 2015, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
- 1. Technical Field
- Exemplary aspects of the present disclosure generally relate to an optical system and an imaging device incorporating the optical system.
- 2. Related Art
- An imaging system including a plurality of wide angle lenses is known, in which the respective wide angle lenses form subject images with the peripheral portions of the respective images overlapping each other, thereby joining the subject images together to obtain a wide view image. Such an imaging system is used in a spherical imaging system, for example.
- Wide angle lenses, which are also called fish-eye lenses, have four projection methods, such as an orthogonal projection, an equisolid angle projection, an equidistance projection, and a stereographic projection. The orthogonal projection and equisolid angle projection have been widely adopted in fish eye lenses for silver salt cameras. The stereographic projection is suitable for recent digital cameras to improve resolutions in the peripheral portions accompanying advance in image processing technology. In addition, to achieve a good balance between axial and off-axial resolutions, the equidistance projection is suitably applied. In such cases, however, one fish-eye lens is used alone, unlike in the spherical imaging system described above that includes a plurality of fish-eye lenses combined.
- In an aspect of this disclosure, there is provided an improved optical system including a plurality of wide angle lenses to form subject images, each wide angle lens having a peripheral area with a decreased image forming magnification per unit angle of view and an inside area ranging from an optical axis to an inside edge of the peripheral area. The inside area includes a first area ranging from the optical axis toward the peripheral area, the first area having a constant image forming magnification per unit angle of view and a second area ranging from an outside edge of the first area to the inside edge of the peripheral area. The second area has an image forming magnification per unit angle of view that continuously varies in a direction from the outside edge of the first area toward the peripheral area. An image portion formed by the peripheral area of a wide angle lens of the plurality of wide angle lenses overlaps with another image portion formed by the peripheral area of another wide angle lens of the plurality of wide angle lenses. An image portion formed by the inside area of the wide angle lens does not overlap with another image portion formed by the inside area of said another wide angle lens.
- In another aspect of this disclosure, there is provided another improved imaging system, including the optical system described above and an image sensor to convert light having passed through the optical system into an electrical signal to generate an imaged image.
- The aforementioned and other aspects, features, and advantages of the present disclosure will be better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
-
FIG. 1 is a view of an imaging system according to a first embodiment of the present disclosure; -
FIG. 2 is a diagram of spherical aberration of a wide angle lens used as a specific example in an optical system of the imaging system; -
FIG. 3 is a diagram of astigmatism of the wide angle lens used as a specific example in the optical system of the imaging system; -
FIG. 4 is a diagram of coma aberration of the wide angle lens used as a specific example in the optical system of the imaging system; -
FIG. 5 is a diagram of a modulation transfer function (MTF) of the wide angle lens used as a specific example in the optical system of the imaging system; -
FIG. 6 is an illustration of a projection method of the wide angle lens used as a specific example in the optical system of the imaging system; -
FIG. 7 is a diagram of an image forming magnification per unit angle of view of the wide angle lens used as a specific example in the optical system of the imaging system; -
FIG. 8 is a diagram of an image forming magnification per unit angle of view of a wide angle lens used as a comparative example in the optical system of the imaging system; -
FIG. 9 is a diagram of relations between MTF values with respect to a spatial frequency of 200 LP/mm and half angles of view for a specific wide angle lens and a comparative wide angle lens, respectively; and -
FIG. 10 is a diagram of a resolution for each pixel on a light receiving surface of an image sensor. - The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted.
- In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner and achieve similar results.
- Although the embodiments are described with technical limitations with reference to the attached drawings, such description is not intended to limit the scope of the disclosure and all of the components or elements described in the embodiments of this disclosure are not necessarily indispensable.
- Referring now to the drawings, embodiments of the present disclosure are described below. In the drawings for explaining the following embodiments, the same reference codes are allocated to elements (members or components) having the same function or shape and redundant descriptions thereof are omitted below.
- A description is provided of embodiments below.
-
FIG. 1 is a view of an imaging system according to a first embodiment. - In
FIG. 1 , reference numeral “1 b” denotes the imaging system according to the first embodiment. - The imaging system lb is a “full spherical imaging system” including two wide angle lenses.
- As illustrated in
FIG. 1 , the imaging system lb includes a firstwide angle lens 10 b, a first cover glass CGb, a first image sensor ISb, a secondwide angle lens 10 c, a second cover glass CGc, and a second image sensor ISc. - The first
wide angle lens 10 b and the secondwide angle lens 10 c are of the “same technical specification (spec.)”. A description of the firstwide angle lens 10 b is given below. In this case, the reference numerals in parentheses refer to the corresponding elements of the secondwide angle lens 10 c, respectively. - The first
wide angle lens 10 b (10 c) includes a “front group, a rear group, an aperture, and a prism”. - The “front group” consists of two negative meniscus lenses L1 b (L1 c) and L2 b (L2 c), having a negative refractive power as a whole. The front group receives rays with a wide angle of view greater than 180 degrees.
- The “rear group” consists of five lenses, that is, a lens L3 b (L3 c), a lens L4 b (L4 c), a lens L5 b (L5 c), a lens L6 b (L6 c), and a lens L7 b (L7 c), which are disposed in this order toward the image side (the image sensor side).
- The prism PSb (PSc) is disposed between the front group and the rear group. The optical axis OA2 b (OA2 c) of the front group is bent by 90 degrees. That is, the optical axis of the rear group is perpendicular to the optical axis OA2 b (OA2 c) of the front group, and to a light receiving surface of the image sensor ISb (ISc).
- The prism PSb (PSc) is a right-angle prism having a slanted surface formed with a reflection surface MSb (MSc). The prism PSb and the prism Psc are integrated with each other, having the reflection surface MSb in contact with the reflection surface MSc.
- Among the lenses L3 b (L3 c), L5 b (L5 c), L6 b (L6 c), and L7 b (L7 c) that constitute the rear group, the lens L3 b (L3 c) is disposed closest to the prism PSb (PSc). An
aperture 4 b (4 c) is disposed in contact with the prism-side surface of the lens L3 b (L3 c). - Among the lenses L3 b (L3 c), L4 b (L4 c), L5 b (L5 c), L6 b (L6 c), and L7 b (L7 c) that constitute the rear group, the lenses L4 b (L4 c) is a “biconvex lens”.
- The lens L5 b (L5 c) is a “biconvex lens”, and the lens L6 b (L6 c) is a “biconcave lens”. The lens L5 b (L5 c) as the biconvex lens is cemented to the lens L6 b (L6 c) as the biconcave lens.
- The most-image-side lens L7 b (L7 c) is a “biconvex lens”.
- Table 1 below represents one example of data regarding the
wide angle lens 10 b (10 c) ofFIG. 1 . -
TABLE 1 Surface Radii of Refractive Abbe Numbers Types Curvature Thicknesses Indices Numbers 1 Spherical 17.08 1.2 1.882997 40.76511 Surface 2 Spherical 6.19 2.7 Surface 3 Aspherical 26.3 0.8 1.882023 37.2213 Surface 4 Aspherical 3.26 4.23 Surface 5 — Infinity 5 1.834 37.16049 6 — Infinity 1.54 Aperture — Infinity 0 8 Spherical 12.2 1 1.84666 23.77794 Surface 9 Spherical −21.46 0.51 Surface 10 Aspherical 9.85 1.23 1.6935 53.20078 Surface 11 Aspherical −11.58 0.35 Surface 12 Spherical 6.57 2 1.744002 44.71997 Surface 13 Spherical −3.64 0.74 1.945945 17.98426 Surface 14 Spherical 3.69 0.36 Surface 15 Aspherical 4.43 1.87 1.58913 61.25089 Surface 16 Aspherical −7.46 0.9 Surface 17 — Infinity 0.5 1.51633 64.14202 18 — Infinity 0.5 - In Table 1, “Surface Numbers” refers to the numbers of lens surfaces sequentially numbered from the object side. Surface number 7 corresponds to “surface of the aperture”. “Types” refers to the types of lens surfaces, such as a “spherical surface” and an “aspherical surface”. “Thicknesses” refers to the distances between lens surfaces. “Refractive indices” and “Abbe numbers” respectively refer to refractive indices and the Abbe numbers of lens material with respect to a sodium D line. The “radius of curvature” of an aspherical surface is a “paraxial radius of curvature”. The unit of length, which is a dimension, is mm unless otherwise mentioned.
- In Table 1,
surface numbers - Aspherical surface is expressed by the following formula.
-
X=(H 2 / R)/[1+{1−K(H/r)2}1/2 ]+C4·H 4 +C6·H 6 +C8·H 8 +C10·H 10+ . . . - In the formula, X denotes a displacement along the direction of the optical axis at a position of a height H from the optical axis to the peak of a surface. K denotes a constant of the cone, and “C4, C6, C8, C10 . . . ” refer to aspherical surface coefficients. R refers to a “paraxial radius of curvature”.
- In Table 1, regarding each of the aspherical surfaces (
surface numbers - [Data Regarding Aspherical Surface]
- Surface number 3: C4=0.002491, C8=4.63×10−7.
- Surface number 4: C4=0.003451, C6=0.000504, and C10=1.45×10−5.
- Surface number 10: C4=−0.00235, and C6=−0.00025.
- Surface number 11: C4=−0.00217, and C6=−0.00028.
- Surface number 15: C4=−0.00167, C6=−0.00031, C8=3.07×10−5, and C10=3.12×10−5.
- Surface number 16: C4=0.004209, C6=−0.00141, C8=0.000474, and C12=2.02 ×10−6.
- The asperical surface coefficients for orders not listed in the respective surface numbers are all 0.
- Wide angle lenses satisfying the data shown in Table 1 and data regarding the aspherical surfaces described above are referred to as a “wide angle lens as a specific example (which is also referred to as a specific wide angle lens)”.
- Regarding a specific
wide angle lens 10 b (10 c), a full angle of view is 200 degrees (a half angle of view of 100 degrees). An area, in which a half angle of view ranges from 90 through 100 degrees, corresponds to a “peripheral area” of the lens. Of subject images formed in the light receiving surfaces of the image sensors ISb and ISc, image portions formed with half angles of view ranging from 90 through 100 degrees in thewide angle lenses -
FIGS. 2 through 4 illustrate various types of aberration in the specificwide angle lens 10 b (10 c).FIG. 2 is a diagram of spherical aberration.FIG. 3 is a diagram of astigmatism.FIG. 4 is a diagram of coma aberration. As is clear from the diagrams, the specificwide angle lens 10 b (10 c) has a favorable performance. -
FIG. 5 is a diagram of modulation transfer functions (MTF) of the specificwide angle lens 10 b (10 c) with respect to half angles of view of 30, 60, and 90 degrees in the inside area of the lens. The lateral axis ofFIG. 5 denotes spatial frequency (from 0 through 200 in line pair (LP)/mm). - The characteristics of the MTF are represented with respect to the tangential direction indicated by T in the drawing and with respect to the sagittal direction indicated by S in the
FIG. 5 . - The specific wide angle lens has favorable MTF characteristics. However, with increases in the spatial frequency and half angle of view, the MTF decreases. As a result, the resolution is likely to decrease.
- In the present embodiment, a plurality of wide angle lenses constitute the optical system OS. Each wide angle lens has the inside area and the peripheral area. The inside area includes a first area ranging from the optical axis toward the peripheral area and a second area ranging from the outside edge of the first area to the inside edge of the peripheral area of the lens.
- In the first area, an image forming magnification of a subject image per unit angle of view is constant. In the peripheral area, the image forming magnification of a subject image per unit angle of view decreases as compared to the inside area of the lens. In the second area, the image forming magnification of a subject image per unit angle of view continuously varies in a direction from the outside edge of the first area toward the peripheral area.
- A detailed description is given below.
- The optical system OS according to the present embodiment includes two
wide angle lenses -
FIG. 6 is a diagram of relations between half angles of view and image heights in the wide angle lens as a specific example (specific wide angle lens). - In
FIG. 6 , the half angles of view and image heights are plotted for the “equidistant projection” and the “optical system according to the present embodiment”, respectively. - The “optical system according to the present embodiment” refers to the specific wide angle lens.
- In the equidistant projection, with an increase in the “half angle of view” in the lateral axis, the image height linearly increases.
- The specific wide angle lens represents almost the same “relations between half angles of view and image heights” as in the equidistant projection, while exhibiting a slight deviation from each other. The specific wide lens is designed to adopt the “equidistant projection in the inside area of the lens”. However, actual lens products exhibit a slight deviation in the relations between half angles of view and image heights, from those of the equidistant projection.
- In
FIG. 6 , the image height in the vertical axis is Y, and the half angle of view in the lateral axis is θ. The “image forming magnification per unit angle of view (variation in the image height per unit angle of view)” is dY/dθ. -
FIG. 7 is a diagram of the “image forming magnification per unit angle of view (dY/dθ)”in the wide angle lens as a specific example (the specific wide angle lens). - The curve illustrated in
FIG. 7 is obtained by differentiating a curve representing the “optical system according to the present embodiment” inFIG. 6 by angle of view (θ). - In
FIG. 7 , “I” refers to the first area, and “II” refers to the second area. Further, “III” refers to the peripheral area in which the half angle of view ranges from 90 through 100 degrees. “I” and “II” correspond to the inside area of the lens. - As illustrated in
FIG. 7 , the inside area of the lens includes the first area I ranging from the optical axis (which is 0 in the lateral axis) toward the peripheral area III and the second area II ranging from the end of the first area Ito the beginning of the peripheral area III. In the first area I, an image forming magnification of a subject image per unit angle of view is constant. In the peripheral area III, the image forming magnification of a subject image per unit angle of view decreases as compared to the inside area of the lens. In the second area II, the image forming magnification of a subject image per unit angle of view continuously varies in a direction from the end of the first area I toward the peripheral area III. - In fact, the value of “dY/dθ” in the first area I slightly decreases in a direction toward the second area II, which means that the image forming magnification per unit angle of view (dY/dθ) is not exactly constant in the first area 1. However, such a case, in which values are considered substantially constant, applies to the case in which “the image forming magnification of a subject image per unit angle of view is constant in the first area I”.
- As a comparative example relative to the specific example of the wide angle lens (specific wide angle lens), another wide angle lens (hereinafter, referred to as a comparative wide angle lens or a wide angle lens as a comparative example) is prepared, in which the value of “dY/dθ” varies over the entire range of the areas from the optical axis through the peripheral area of the lens, as illustrated in
FIG. 8 .FIG. 8 illustrates the first area I, the second area II, and the peripheral area III in the same manner as in the specific example (FIG. 7 ). - In the comparative wide angle lens of
FIG. 8 , the value of “dY/dθ” increases with a downward-convex curve in the first area I, and monotonically decreases in the peripheral area III. In the second area II, the value of “dY/dθ” continuously varies in a direction from the end of the first area I toward the peripheral area III. That is, the first area I of the inside area in the comparative wide angle lens adopts the stereographic projection. -
FIG. 9 is a diagram of relations between MTF values (in the vertical axis) with respect to a spatial frequency of 200 LP/mm and half angles of view (in the lateral axis) for the specific wide angle lens and the comparative wide angle lens, respectively. A solid line and a broken line are used for the comparative wide angle lens and the specific wide angle lens, respectively. - Hereinafter, MTF values with respect to a spatial frequency of 200 LP/mm are referred to simply as “
MTF 200”. That is,FIG. 9 is a diagram of variations inMTF 200 in accordance with half angles of view in the comparative wide angle lens (indicated by the solid line) and the specific wide angle lens (indicated by the broken line), respectively. In other words,FIG. 9 represents variations in resolution in accordance with half angles of view. - As can be found from
FIG. 9 ,MTF 200, which represents MTF values at a high spatial frequency of 200 LP/mm, decreases with an increase in half angle of view in the comparative wide angle lens. In the specific wide angle lens,MTF 200 remains favorable up to a maximum angle of view. - Now, referring to
FIG. 10 , the broken line is obtained by multiplying variation in “image forming magnification per unit angle of view (dY/dθ) in the specific wide angle lens” inFIG. 7 by variation in “MTF 200” in accordance with half angles of view indicated by the broken line inFIG. 9 . - The solid line is obtained by multiplying variation in “image forming magnification per unit angle of view (dY/dθ) in the comparative wide angle lens” in
FIG. 8 by variation in “MTF 200” in accordance with half angle of vies indicated by the solid line inFIG. 9 . The “multiplication of dY/dθ andMTF 200” corresponds to a “resolution for each pixel” on the light receiving surface of the image sensor. - The “resolution for each pixel” in the comparative wide angle lens maintains substantially constant from the optical axis to the outermost edge of the peripheral area of the lens, and slightly increases with an increased half angle of view. That is, the comparative wide angle lens has a high resolution in the peripheral area, thus having a favorable performance.
- In contrast, the “resolution for each pixel” in the specific wide angle lens monotonically decreases from the optical axis to the outermost edge of the peripheral area of the lens. The “resolution for each pixel” in the specific wide angle lens is higher over substantially the entire range of the inside area of the lens than the comparative wide angle lens does.
- Thus, an actually joined image generated by the specific wide angle lens has a high resolution over the entire area of the image. In view of resolution and projection method of optical systems including wide angle lenses, the resolution is preferably higher over the entirety of the light receiving surface of the image sensor.
- Therefore, the optical system according to the present embodiment including the specific wide angle lens has a higher performance than the optical system including the comparative wide angle lens.
- As illustrated in
FIG. 10 , the “resolution for each pixel” in the peripheral area is lower in the specific wide angle lens than the comparative wide angle lens. - However, such a low resolution in the peripheral area of the lens may not adversely affect an actual spherical image to be generated.
- This is because image portions formed by the peripheral areas of the lenses overlap with each other, which are not used for an actually generated spherical image. In addition, the overlapped image portions formed by the peripheral areas include a double amount of data with respect to the identical image. This is the same as an increase in light receiving area in a photosensor with respect to the image portions formed by the peripheral areas, which corresponds to an increase in magnification per unit angle of view. Therefore, even with a monotonical decrease in image forming magnification per unit angle of view as indicated by the broken line in
FIG. 10 , a sufficient amount of data for compensation is obtained to image a spherical image with a uniform quality over the entire 360-degree space. - Further, the image portions formed by the peripheral areas of the respective two wide angle lenses are used as reference data representing the identical image to be joined (stitched) together, thereby generating a spherical image.
- The configuration according to the present embodiment achieves a novel optical system including a plurality of wide angle lenses. Further, the configuration according to the present embodiment produces optical systems and imaging systems as described below.
- —Aspect 1—
- According to Aspect 1, an optical system OS, includes: a plurality of
wide angle lenses - —Aspect 2—
- The optical system OS according to Aspect 1, the inside area of each wide angle lens has a equidistance projection.
- —Aspect 3—
- In the optical system OS according to Aspect 1 or 2, the plurality of wide angle lenses is two
wide angle lenses - —Aspect 4—
- In the optical system OS according to Aspect 3, each of the two
wide angle lenses - —
Aspect 5— - In the optical system OS according to Aspect 4, each of the two
wide angle lenses - —Aspect 6—
- In the optical system OS according to
Aspect 5, each of the twowide angle lenses - —Aspect 7—
- In the optical system OS according to Aspect 6, the transparent body PSb (PSc) having the reflection surface MSb (MSc) is a prism.
- —Aspect 8—
- An imaging system includes the optical system OS according to any one of Aspect 1 through Aspect 7, and an image sensor to convert light having passed through the optical system OS into an electrical signal to generate an imaged image.
- —Aspect 9—
- In the imaging system according to Aspect 8, overlapped image portions formed by the plurality of wide angle lenses are joined to display the imaged image
- Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and a variety of modifications can naturally be made within the scope of the present disclosure.
- The aspects of optical system including two wide angle lenses according to the present embodiment is expanded to general use. That is, in some embodiments, an optical system with n or more numbers of wide angle lenses is applicable, having a full angle of view of A degrees, which is greater than 360/n. The optical system includes a first area with a substantially constant magnification per unit angle of view, a peripheral area with a decreased magnification per unit angle of view, and a second area between the first area and the peripheral area, in which the magnification continuously varies. In this case, n is a natural number not less than 2.
- For example, an optical system including three wide angle lenses is used in some embodiments, having a full angle of view of A degrees (e.g., 140 degrees) greater than 360/3 (i.e., 120 degrees for each lens). In the optical system, the wide angle lenses are radially disposed on the same plane, each including an image sensor to constitute an imaging system. With such an optical system, 360-degree horizontal panoramic images are imaged.
- Notwithstanding that the images obtained by such an imaging system are not full spherical images, the imaging system capable of imaging horizontal panoramic images is implemented as a vehicle mounted camera or a security camera.
- For another example, an optical system including four wide angle lenses is used as a spherical imaging system in some embodiment, having a full angle of view of 140 degrees (A =140). In the optical system, the four wide angle lenses are spatially combined in a radial manner to form a regular tetrahedron. This spherical imaging system images spherical images with a solid angle of 4π radian.
- Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the above teachings, the present disclosure may be practiced otherwise than as specifically described herein. With some embodiments having thus been described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the present disclosure and appended claims, and all such modifications are intended to be included within the scope of the present disclosure and appended claims.
Claims (9)
1. An optical system, comprising:
a plurality of wide angle lenses to form subject images, each wide angle lens having a peripheral area with a decreased image forming magnification per unit angle of view and an inside area ranging from an optical axis to an inside edge of the peripheral area,
the inside area including:
a first area ranging from the optical axis toward the peripheral area, the first area having a constant image forming magnification per unit angle of view; and
a second area ranging from an outside edge of the first area to the inside edge of the peripheral area, the second area having an image forming magnification per unit angle of view that continuously varies in a direction from the outside edge of the first area toward the peripheral area,
wherein an image portion formed by the peripheral area of a wide angle lens of the plurality of wide angle lenses overlaps with another image portion formed by the peripheral area of another wide angle lens of the plurality of wide angle lenses, and
wherein an image portion formed by the inside area of the wide angle lens does not overlap with another image portion formed by the inside area of said another wide angle lens.
2. The optical system according to claim 1 ,
wherein the inside area of each wide angle lens has an equidistance projection.
3. The optical system according to claim 1 ,
wherein the plurality of wide angle lenses is two wide angle lenses each having a full angle of view equal to or greater than 180 degrees.
4. The optical system according to claim 3 ,
wherein each of the two wide angle lenses has the same technical specification and has a half angle of view greater than 90 degrees in the peripheral area.
5. The optical system according to claim 4 ,
wherein each of the two wide angle lenses includes a front group having a negative refractive power and a rear group having a positive refractive power.
6. The optical system according to claim 5 ,
wherein each of the two wide angle lenses includes, between the front group and the rear group, a transparent body having a reflection surface to bend a bundle of rays coming from the front group, toward the rear group, and
wherein the reflection surface of the transparent body of one of the two wide angle lenses is adjacent to or in contact with the reflection surface of the transparent body of another of the two wide angle lenses.
7. The optical system according to claim 6 ,
wherein the transparent body having the reflection surface is a prism.
8. An imaging system, comprising:
the optical system according to claim 1 ; and
an image sensor to convert light having passed through the optical system into an electrical signal to generate an imaged image.
9. The imaging system according to claim 8 ,
wherein overlapped image portions formed by the plurality of wide angle lenses are joined to display the imaged image.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015-105614 | 2015-05-25 | ||
JP2015105614A JP6736262B2 (en) | 2015-05-25 | 2015-05-25 | Optical system and imaging system |
Publications (2)
Publication Number | Publication Date |
---|---|
US20160353020A1 true US20160353020A1 (en) | 2016-12-01 |
US9930254B2 US9930254B2 (en) | 2018-03-27 |
Family
ID=57397724
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/137,404 Active 2036-10-15 US9930254B2 (en) | 2015-05-25 | 2016-04-25 | Optical system and imaging system incorporating the same |
Country Status (2)
Country | Link |
---|---|
US (1) | US9930254B2 (en) |
JP (1) | JP6736262B2 (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170322398A1 (en) * | 2016-05-06 | 2017-11-09 | Sintai Optical (Shenzhen) Co., Ltd. | Panoramic Lens Assembly |
WO2018113011A1 (en) * | 2016-12-21 | 2018-06-28 | 李军明 | Scene generation device, robot and unmanned driving device |
CN109407100A (en) * | 2018-09-21 | 2019-03-01 | 中国科学院长春光学精密机械与物理研究所 | A kind of compact infrared scan tracking system |
US10234659B2 (en) * | 2016-03-28 | 2019-03-19 | Apple Inc. | Folded lens system with four refractive lenses |
US10701252B2 (en) | 2018-03-05 | 2020-06-30 | Ricoh Company, Ltd. | Imaging optical system, imaging system, and imaging apparatus |
US10852503B2 (en) | 2018-03-20 | 2020-12-01 | Ricoh Company, Ltd. | Joint structure |
US10942343B2 (en) | 2018-03-20 | 2021-03-09 | Ricoh Company, Ltd. | Optical system and imaging apparatus |
US20220086316A1 (en) * | 2019-02-07 | 2022-03-17 | Yuji TORIUMI | Optical system, imaging system, and imaging apparatus |
US11378871B2 (en) | 2018-03-02 | 2022-07-05 | Ricoh Company, Ltd. | Optical system, and imaging apparatus |
US11445095B2 (en) | 2018-03-20 | 2022-09-13 | Ricoh Company, Ltd. | Image-sensor fixing structure |
US11595631B2 (en) | 2019-03-14 | 2023-02-28 | Ricoh Company, Ltd. | Imaging device, image capturing optical system, and movable apparatus |
US20230176341A1 (en) * | 2017-06-02 | 2023-06-08 | Owl Labs, Inc. | Wide angle lens and camera system for peripheral field of view imaging |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7010749B2 (en) * | 2018-03-30 | 2022-01-26 | 京セラ株式会社 | Imaging lens unit |
JP7408053B2 (en) | 2019-12-02 | 2024-01-05 | 株式会社ニコン | spherical camera |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130050405A1 (en) * | 2011-08-26 | 2013-02-28 | Kensuke Masuda | Imaging system and imaging optical system |
US20130242040A1 (en) * | 2012-03-16 | 2013-09-19 | Kensuke Masuda | Imaging system |
US20140071226A1 (en) * | 2012-09-11 | 2014-03-13 | Hiroyuki Satoh | Image capture system and imaging optical system |
US20140132709A1 (en) * | 2011-07-25 | 2014-05-15 | Hiroyuki Satoh | Wide-angle lens and imaging device |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3008926B2 (en) * | 1998-04-16 | 2000-02-14 | 株式会社ニコン | Fish icon barter and photographing lens system equipped with the fish icon barter |
JP6142467B2 (en) | 2011-08-31 | 2017-06-07 | 株式会社リコー | Imaging optical system, omnidirectional imaging apparatus, and imaging system |
-
2015
- 2015-05-25 JP JP2015105614A patent/JP6736262B2/en active Active
-
2016
- 2016-04-25 US US15/137,404 patent/US9930254B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140132709A1 (en) * | 2011-07-25 | 2014-05-15 | Hiroyuki Satoh | Wide-angle lens and imaging device |
US20130050405A1 (en) * | 2011-08-26 | 2013-02-28 | Kensuke Masuda | Imaging system and imaging optical system |
US20130242040A1 (en) * | 2012-03-16 | 2013-09-19 | Kensuke Masuda | Imaging system |
US20140071226A1 (en) * | 2012-09-11 | 2014-03-13 | Hiroyuki Satoh | Image capture system and imaging optical system |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10234659B2 (en) * | 2016-03-28 | 2019-03-19 | Apple Inc. | Folded lens system with four refractive lenses |
US9958651B2 (en) * | 2016-05-06 | 2018-05-01 | Sintai Optical (Shenzhen) Co., Ltd. | Panoramic lens assembly |
US20170322398A1 (en) * | 2016-05-06 | 2017-11-09 | Sintai Optical (Shenzhen) Co., Ltd. | Panoramic Lens Assembly |
WO2018113011A1 (en) * | 2016-12-21 | 2018-06-28 | 李军明 | Scene generation device, robot and unmanned driving device |
US20230176341A1 (en) * | 2017-06-02 | 2023-06-08 | Owl Labs, Inc. | Wide angle lens and camera system for peripheral field of view imaging |
US11378871B2 (en) | 2018-03-02 | 2022-07-05 | Ricoh Company, Ltd. | Optical system, and imaging apparatus |
US10701252B2 (en) | 2018-03-05 | 2020-06-30 | Ricoh Company, Ltd. | Imaging optical system, imaging system, and imaging apparatus |
US10852503B2 (en) | 2018-03-20 | 2020-12-01 | Ricoh Company, Ltd. | Joint structure |
US10942343B2 (en) | 2018-03-20 | 2021-03-09 | Ricoh Company, Ltd. | Optical system and imaging apparatus |
US11445095B2 (en) | 2018-03-20 | 2022-09-13 | Ricoh Company, Ltd. | Image-sensor fixing structure |
CN109407100A (en) * | 2018-09-21 | 2019-03-01 | 中国科学院长春光学精密机械与物理研究所 | A kind of compact infrared scan tracking system |
US20220086316A1 (en) * | 2019-02-07 | 2022-03-17 | Yuji TORIUMI | Optical system, imaging system, and imaging apparatus |
US11595631B2 (en) | 2019-03-14 | 2023-02-28 | Ricoh Company, Ltd. | Imaging device, image capturing optical system, and movable apparatus |
Also Published As
Publication number | Publication date |
---|---|
US9930254B2 (en) | 2018-03-27 |
JP6736262B2 (en) | 2020-08-05 |
JP2016218352A (en) | 2016-12-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9930254B2 (en) | Optical system and imaging system incorporating the same | |
US10627603B2 (en) | Imaging lens assembly, image capturing unit and electronic device | |
US10649185B2 (en) | Imaging system and imaging optical system | |
CN108957687B (en) | Photographing lens system, image capturing device and electronic device | |
CN109407272B (en) | Electronic device | |
US9244251B2 (en) | Wide-angle photographic lens system enabling correction of distortion | |
US9001433B2 (en) | Zoom lens and imaging apparatus | |
US9864166B2 (en) | Imaging lens and imaging apparatus | |
US20150085383A1 (en) | Wide-angle photographic lens system enabling correction of distortion | |
CN115128770B (en) | Optical lens | |
CN112987252A (en) | Optical system, infrared receiving module and electronic equipment | |
CN115128771B (en) | Optical lens | |
CN115128769A (en) | Optical lens | |
US20140240849A1 (en) | Zoom lens and imaging apparatus | |
CN115079384A (en) | Optical lens | |
CN113296237A (en) | Optical system, image capturing module and electronic equipment | |
US9841582B2 (en) | Imaging lens and imaging apparatus | |
US20170059817A1 (en) | Imaging lens and imaging apparatus | |
CN115097615B (en) | Optical lens | |
JP5783314B2 (en) | Spherical optical system and imaging system | |
WO2021065091A1 (en) | Lens system, imaging device and imaging system | |
JP5298878B2 (en) | Imaging lens, camera device, and portable information terminal device | |
CN115128781B (en) | Optical lens | |
CN116990942B (en) | Optical lens | |
CN115113379B (en) | Optical lens |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: RICOH COMPANY, LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SATOH, HIROYUKI;REEL/FRAME:038369/0782 Effective date: 20160418 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |